I suggest you ...

Plug the headphones and hear yourself in real time

A great feature of a dictaphone is that it allows you also to coach and practice your voice. This can be even better if you can hear yourself in the headphones while speaking.

Having a switchable option that would allow you to hear yourself in real time, even when the app is in the background and only when you plug in the headphones, would be great.

This is what a small IOS app like "Speaker's coach", that of course lacks many of the features Dictamus have, can do with it's small embedded dictaphone.

Once you add this feature you could then also add the possibility to voice over and re-record samples, while you hear them over your headphones. This an important feature if you want to improve on your own voice recordings.